I think it is pretty obvious. An ideology is something that has a very narrow set of answers to every problem. It can easily preempt much or even any actual thinking. On a forum one can easily end up in a screaming battle between ideologies that has exactly zero informational content. If one happens to already know the ideologies in question, and one probably does because there is not really much that is new in this area, one could write out the whole discussion just by oneself in advance and not be off by much.